The invention relates to a cassette for a record carrier which can be scanned by scanning means for the purpose of making and/or reproducing recordings, which cassette has a substantially rectangular cassette housing accommodating the record carrier and having at least one access area for the record carrier, in which area the scanning means can enter into cooperation with the record carrier for the purpose of scanning, at least one sliding cover which is guided on the cassette housing so as to be movable parallel to a direction of movement, which cover is movable between a closed position, in which the cover at least partly covers the access area, and an open position, in which the cover exposes the access area, and comprises at least one plate-shaped portion extending parallel to a main wall of the cassette housing and having an edge zone of predetermined length which extends substantially parallel to the direction of movement of the sliding cover, and hold-down means connected to the cassette housing and engaging over the plate-shaped portion in the edge zone thereof, which hold-down means thus prevent the plate-shaped portion of the sliding cover from being lifted off the main wall of the cassette housing.
A cassette of the type defined in the opening paragraph is known from EO 0,218,231 A2. This is a cassette for a round disc-shaped rotatable record carrier. The known cassette has an access area in the form of a slot-like opening in each of the two main walls of the cassette housing. Through each of the two openings a magnetic head can be made to cooperate with the round disc-shaped record carrier in the cassette housing for the purpose of scanning. In order to cover the two openings there is provided a U-shaped sliding cover whose web portion is connected to a cover support which is slidably guided in the cassette housing. At the location of their free ends, i.e. in their edge zones, a pressure plate serving as a hold-down means overlies each of the plate-shaped flanges of the sliding cover to prevent the plate-shaped flanges to be lifted off the main walls of the cassette. Parallel to the direction of movement of the sliding cover the pressure plates are dimensioned in such a way that both when the sliding cover is its closed position and in its open position the pressure plates overlie the edge zones of the plate-shaped flanges over their whole length. As a result of this comparatively large dimension of the pressure plates parallel to the direction of movement of the sliding cover the problem arises that in the case of larger temperature fluctuations these pressure plates tend to warp, which disturbs their correct hold-down function or results in excessive frictional forces being exerted on the sliding cover by the pressure plates, which may lead to a poor slidability and even to jamming of the sliding cover. Moreover, such comparatively long pressure plates, which cover the entire range of movement of the edge zone of the sliding cover, have the problem that dirt particles may settle in the grooved area which extends over the entire range of movement between a pressure plate and the facing main wall of the cassette housing and thereby impair a correct movement of the sliding cover. Such pressure plates may be integral with the cassette housing, but this complicates the production of the cassette housing, or they may be constructed as separate parts connected to the cassette housing by, for example, adhesive means or ultrasonic welding; however, such separate pressure plates are difficult to manufacture accurately to size and are comparatively difficult to handle during mounting on the cassette housing, particularly in the case of automated mounting because they are difficult to align and because they have the undesirable tendency to become warped as a result of their low stiffness.